Anthropic

The Anthropic adapter provides access to Claude models, including Claude Sonnet 4.5, Claude Opus 4.5, and more.

Installation

npm install @tanstack/ai-anthropic

npm install @tanstack/ai-anthropic

Basic Usage

typescript

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Hello!" }],
});

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Hello!" }],
});

Basic Usage - Custom API Key

typescript

import { chat } from "@tanstack/ai";
import { createAnthropicChat } from "@tanstack/ai-anthropic";

const adapter = createAnthropicChat(process.env.ANTHROPIC_API_KEY!, {
  // ... your config options
});

const stream = chat({
  adapter: adapter("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Hello!" }],
});

import { chat } from "@tanstack/ai";
import { createAnthropicChat } from "@tanstack/ai-anthropic";

const adapter = createAnthropicChat(process.env.ANTHROPIC_API_KEY!, {
  // ... your config options
});

const stream = chat({
  adapter: adapter("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Hello!" }],
});

Configuration

typescript

import { createAnthropicChat, type AnthropicChatConfig } from "@tanstack/ai-anthropic";

const config: Omit<AnthropicChatConfig, 'apiKey'> = {
  baseURL: "https://api.anthropic.com", // Optional, for custom endpoints
};

const adapter = createAnthropicChat(process.env.ANTHROPIC_API_KEY!, config);

import { createAnthropicChat, type AnthropicChatConfig } from "@tanstack/ai-anthropic";

const config: Omit<AnthropicChatConfig, 'apiKey'> = {
  baseURL: "https://api.anthropic.com", // Optional, for custom endpoints
};

const adapter = createAnthropicChat(process.env.ANTHROPIC_API_KEY!, config);

Example: Chat Completion

typescript

import { chat, toServerSentEventsResponse } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";

export async function POST(request: Request) {
  const { messages } = await request.json();

  const stream = chat({
    adapter: anthropicText("claude-sonnet-4-5"),
    messages,
  });

  return toServerSentEventsResponse(stream);
}

import { chat, toServerSentEventsResponse } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";

export async function POST(request: Request) {
  const { messages } = await request.json();

  const stream = chat({
    adapter: anthropicText("claude-sonnet-4-5"),
    messages,
  });

  return toServerSentEventsResponse(stream);
}

Example: With Tools

typescript

import { chat, toolDefinition } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { z } from "zod";

const searchDatabaseDef = toolDefinition({
  name: "search_database",
  description: "Search the database",
  inputSchema: z.object({
    query: z.string(),
  }),
});

const searchDatabase = searchDatabaseDef.server(async ({ query }) => {
  // Search database
  return { results: [] };
});

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages,
  tools: [searchDatabase],
});

import { chat, toolDefinition } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { z } from "zod";

const searchDatabaseDef = toolDefinition({
  name: "search_database",
  description: "Search the database",
  inputSchema: z.object({
    query: z.string(),
  }),
});

const searchDatabase = searchDatabaseDef.server(async ({ query }) => {
  // Search database
  return { results: [] };
});

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages,
  tools: [searchDatabase],
});

Model Options

Anthropic supports various provider-specific options:

typescript

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages,
  modelOptions: {
    max_tokens: 4096,
    temperature: 0.7,
    top_p: 0.9,
    top_k: 40,
    stop_sequences: ["END"],
  },
});

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages,
  modelOptions: {
    max_tokens: 4096,
    temperature: 0.7,
    top_p: 0.9,
    top_k: 40,
    stop_sequences: ["END"],
  },
});

Thinking (Extended Thinking)

Enable extended thinking with a token budget. This allows Claude to show its reasoning process, which is streamed as thinking chunks:

typescript

modelOptions: {
  thinking: {
    type: "enabled",
    budget_tokens: 2048, // Maximum tokens for thinking
  },
}

modelOptions: {
  thinking: {
    type: "enabled",
    budget_tokens: 2048, // Maximum tokens for thinking
  },
}

Note: max_tokens must be greater than budget_tokens. The adapter automatically adjusts max_tokens if needed.

Prompt Caching

Cache prompts for better performance and reduced costs:

typescript

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [
    {
      role: "user",
      content: [
        {
          type: "text",
          content: "What is the capital of France?",
          metadata: {
            cache_control: {
              type: "ephemeral",
            },
          },
        },
      ],
    },
  ],
});

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [
    {
      role: "user",
      content: [
        {
          type: "text",
          content: "What is the capital of France?",
          metadata: {
            cache_control: {
              type: "ephemeral",
            },
          },
        },
      ],
    },
  ],
});

Summarization

Anthropic supports text summarization:

typescript

import { summarize } from "@tanstack/ai";
import { anthropicSummarize } from "@tanstack/ai-anthropic";

const result = await summarize({
  adapter: anthropicSummarize("claude-sonnet-4-5"),
  text: "Your long text to summarize...",
  maxLength: 100,
  style: "concise", // "concise" | "bullet-points" | "paragraph"
});

console.log(result.summary);

import { summarize } from "@tanstack/ai";
import { anthropicSummarize } from "@tanstack/ai-anthropic";

const result = await summarize({
  adapter: anthropicSummarize("claude-sonnet-4-5"),
  text: "Your long text to summarize...",
  maxLength: 100,
  style: "concise", // "concise" | "bullet-points" | "paragraph"
});

console.log(result.summary);

Environment Variables

Set your API key in environment variables:

ANTHROPIC_API_KEY=sk-ant-...

ANTHROPIC_API_KEY=sk-ant-...

API Reference

anthropicText(config?)

Creates an Anthropic chat adapter using environment variables.

Returns: An Anthropic chat adapter instance.

createAnthropicChat(apiKey, config?)

Creates an Anthropic chat adapter with an explicit API key.

Parameters:

apiKey - Your Anthropic API key
config.baseURL? - Custom base URL (optional)

Returns: An Anthropic chat adapter instance.

anthropicSummarize(config?)

Creates an Anthropic summarization adapter using environment variables.

Returns: An Anthropic summarize adapter instance.

createAnthropicSummarize(apiKey, config?)

Creates an Anthropic summarization adapter with an explicit API key.

Parameters:

apiKey - Your Anthropic API key
config.baseURL? - Custom base URL (optional)

Returns: An Anthropic summarize adapter instance.

Limitations

Image Generation: Anthropic does not support image generation. Use OpenAI or Gemini for image generation.

Next Steps

Getting Started - Learn the basics
Tools Guide - Learn about tools
Other Adapters - Explore other providers

Provider Tools

Anthropic exposes several native tools beyond user-defined function calls. Import them from @tanstack/ai-anthropic/tools and pass them into chat({ tools: [...] }).

For the full concept, a comparison matrix, and type-gating details, see Provider Tools.

webSearchTool

Enables Claude to run Anthropic's native web search with inline citations. Scope the search with allowed_domains or blocked_domains (mutually exclusive); set max_uses to cap per-turn cost.

typescript

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { webSearchTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-opus-4-6"),
  messages: [{ role: "user", content: "What's new in AI this week?" }],
  tools: [
    webSearchTool({
      name: "web_search",
      type: "web_search_20250305",
      max_uses: 2,
    }),
  ],
});

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { webSearchTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-opus-4-6"),
  messages: [{ role: "user", content: "What's new in AI this week?" }],
  tools: [
    webSearchTool({
      name: "web_search",
      type: "web_search_20250305",
      max_uses: 2,
    }),
  ],
});

Supported models: every current Claude model. claude-3-haiku supports only web_search (not web_fetch). See Provider Tools.

webFetchTool

Lets Claude fetch the contents of a URL directly, useful when you want the model to read a specific page rather than run a search. Takes no required arguments — pass an optional config object to override defaults.

typescript

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { webFetchTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Summarise https://example.com" }],
  tools: [webFetchTool()],
});

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { webFetchTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Summarise https://example.com" }],
  tools: [webFetchTool()],
});

Supported models: Claude Sonnet 4.x and above. See Provider Tools.

codeExecutionTool

Gives Claude a sandboxed code-execution environment so it can run Python snippets, analyse data, and return results inline. Choose the version string that matches your desired API revision.

typescript

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { codeExecutionTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Plot a histogram of [1,2,2,3,3,3]" }],
  tools: [
    codeExecutionTool({ name: "code_execution", type: "code_execution_20250825" }),
  ],
});

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { codeExecutionTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Plot a histogram of [1,2,2,3,3,3]" }],
  tools: [
    codeExecutionTool({ name: "code_execution", type: "code_execution_20250825" }),
  ],
});

Supported models: Claude Sonnet 4.x and above. See Provider Tools.

computerUseTool

Allows Claude to observe a virtual desktop (screenshots) and interact with it via keyboard and mouse events. Provide the screen resolution so Claude can calculate accurate coordinates.

typescript

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { computerUseTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Open the browser and go to example.com" }],
  tools: [
    computerUseTool({
      type: "computer_20250124",
      name: "computer",
      display_width_px: 1024,
      display_height_px: 768,
    }),
  ],
});

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { computerUseTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Open the browser and go to example.com" }],
  tools: [
    computerUseTool({
      type: "computer_20250124",
      name: "computer",
      display_width_px: 1024,
      display_height_px: 768,
    }),
  ],
});

Supported models: Claude Sonnet 3.5 and above. See Provider Tools.

bashTool

Provides Claude with a persistent bash shell session, letting it run arbitrary commands, install packages, or manipulate files on the host. Choose the type string that matches your API revision.

typescript

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { bashTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "List all TypeScript files in src/" }],
  tools: [bashTool({ name: "bash", type: "bash_20250124" })],
});

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { bashTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "List all TypeScript files in src/" }],
  tools: [bashTool({ name: "bash", type: "bash_20250124" })],
});

Supported models: Claude Sonnet 3.5 and above. See Provider Tools.

textEditorTool

Gives Claude a structured text-editor interface for viewing and modifying files using str_replace, create, view, and undo_edit commands. Choose the type string for the API revision you target.

typescript

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { textEditorTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Fix the bug in src/index.ts" }],
  tools: [
    textEditorTool({ type: "text_editor_20250124", name: "str_replace_editor" }),
  ],
});

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { textEditorTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Fix the bug in src/index.ts" }],
  tools: [
    textEditorTool({ type: "text_editor_20250124", name: "str_replace_editor" }),
  ],
});

Supported models: Claude Sonnet 3.5 and above. See Provider Tools.

memoryTool

Enables Claude to store and retrieve information across conversation turns using Anthropic's managed memory service. Call with no arguments to use default configuration.

typescript

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { memoryTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Remember that I prefer metric units" }],
  tools: [memoryTool()],
});

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { memoryTool } from "@tanstack/ai-anthropic/tools";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Remember that I prefer metric units" }],
  tools: [memoryTool()],
});

Supported models: Claude Sonnet 4.x and above. See Provider Tools.

customTool

Creates a tool with an inline JSON Schema input definition instead of going through toolDefinition(). Useful when you need fine-grained control over the schema shape or want to add cache_control. Unlike branded provider tools, customTool returns a plain Tool and is accepted by any chat model.

typescript

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { customTool } from "@tanstack/ai-anthropic/tools";
import { z } from "zod";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Look up user 42" }],
  tools: [
    customTool(
      "lookup_user",
      "Look up a user by ID and return their profile",
      z.object({ userId: z.number() }),
    ),
  ],
});

import { chat } from "@tanstack/ai";
import { anthropicText } from "@tanstack/ai-anthropic";
import { customTool } from "@tanstack/ai-anthropic/tools";
import { z } from "zod";

const stream = chat({
  adapter: anthropicText("claude-sonnet-4-5"),
  messages: [{ role: "user", content: "Look up user 42" }],
  tools: [
    customTool(
      "lookup_user",
      "Look up a user by ID and return their profile",
      z.object({ userId: z.number() }),
    ),
  ],
});

Supported models: all current Claude models. See Provider Tools.

Installation#

Basic Usage#

Basic Usage - Custom API Key#

Configuration#

Example: Chat Completion#

Example: With Tools#

Model Options#

Thinking (Extended Thinking)#

Prompt Caching#

Summarization#

Environment Variables#

API Reference#

anthropicText(config?)#

createAnthropicChat(apiKey, config?)#

anthropicSummarize(config?)#

createAnthropicSummarize(apiKey, config?)#

Limitations#

Next Steps#

Provider Tools#

webSearchTool#

webFetchTool#

codeExecutionTool#

computerUseTool#

bashTool#

textEditorTool#

memoryTool#

customTool#

Installation

Basic Usage

Basic Usage - Custom API Key

Configuration

Example: Chat Completion

Example: With Tools

Model Options

Thinking (Extended Thinking)

Prompt Caching

Summarization

Environment Variables

API Reference

anthropicText(config?)

createAnthropicChat(apiKey, config?)

anthropicSummarize(config?)

createAnthropicSummarize(apiKey, config?)

Limitations

Next Steps

Provider Tools

webSearchTool

webFetchTool

codeExecutionTool

computerUseTool

bashTool

textEditorTool

memoryTool

customTool